Fig. 6: Electrochemical characterisation of symmetric 0, 1 and 5% Mg Li-Mg∣∣Li-Mg cells at varied pressure.

A Areal capacity extracted before a cell potential of 100 mV is reached at a range of pressures, error bars show standard error across multiple samples. B Unidirectional chronopotentiometry of self-symmetric cells at 2.5 MPa. C Ratio of interfacial capacitance before (Q0) and after (Q) unidirectional chronopotentiometry, error bars show standard error across multiple samples. EIS data and fits are available in the repository56. D Ratio of interfacial resistance before (R0) and after (R) unidirectional chronopotentiometry, error bars show standard error across multiple samples. E representative EIS spectra before/after chronopotentiometry for self-symmetric 1% Mg alloy cell at 2.5 MPa fit with equivalent circuit inset in Fig. 3A.